Wide angle telecentric projection lens assembly
US4189211A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 3, 1978 |
| Grant date | Feb 19, 1980 |
| Priority date | — |
| Expiry date | Jan 3, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B13/00
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A wide angle telecentric projection lens system, having a long back focal distance, includes a front lens doublet, comprising negative and positive meniscus lens elements, located in front of an aperture stop, and a rear lens group on the other side of the aperture stop, the rear group comprising a rear lens doublet which includes positive and negative meniscus lens elements, the rear doublet having its curvature reversed relative to the front doublet but having an air space between its component lens elements, plus two biconvex lens elements slightly spaced from each other and from the second doublet. A beam splitting optical prism and/or similar optical element(s) may be included between the rear lens group and the object.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.